1. Field of the Invention
This invention relates to a card edge connector used for connecting an auxiliary card, such as a single-in-line memory (SIMM) module or a dual-in-line memory (DIMM) module, to a master board, such as a mother circuit board, and especially relates to a latching device for a card edge connector by which an auxiliary card can be obliquely inserted into a slot of the connector with its edge and than be rotated to a position parallel to the master board as well as be latched such that contacts located on the edge of the auxiliary card can electrically contact the terminals provided in the slot.
2. Description of the Prior Art
With the popularization of the notebook computer and the progress in manufacturing techniques, the shape or profile of memory is becoming smaller, for example, from a DIP profile to a CSP profile. Moreover, for the sake of convenience, it has become more popular to use a SIMM or DIMM card on which a plurality of memory chips are mounted, and a card edge connector for the installation of that card, to expand the capacity of memory. Many types of card edge connectors have been proposed in recent years. The proposed card edge generally comprises a receptacle housing and two latching arms located at and extended from opposing sides of the housing. There are many kinds of designs for the structure of the latching arm to overcome such problems as strength of the latching arms, convenience of operation, stability of latching, and space being occupied.
For example, it is disclosed in U.S. Pat. No. 5,484,302 a latching device provided with a first arm and a second arm in which the second arm includes a latching unit and a latching release unit. The first arm will be biased towards the second arm for fixing the latching device in a receptacle compartment of a connector when the latching device is inserted into the receptacle compartment. Moreover, a socket having a latching member is disclosed in R.O.C. Patent Application No. 84,100,813, in which a tongue is provided on and protruded from a bottom of a movable part of a latching arm, and a recess for receiving the tongue is provided on a fixed part thereof, such that a vertical motion of the movable part is avoided and motion in an inserting direction of an auxiliary board is limited. Such a patent is contemplated to overcome a drawback that a latching arm is difficult to latch up exactly to an auxiliary board when a SIMM card acting as the auxiliary board is inserted therein. Furthermore, an electrical connector for printed circuit board comprising a body portion and a latching member is disclosed in U.S. Pat. No. 5,632,640 (as well as Japanese Patent Application No. Hei-7-636). The latching member is provided with a round portion to match with the side edge of a circuit card and a pair of retaining arms extending above the round portion to engage another surface of the circuit card. In R.O.C. U.S. Patent Publication No. 313,334, a design utilizing two L-shape locating members to prevent a connector from dropping out a circuit board when it is turned around in a solder furnace is disclosed. The two locating members are respectively provided on a supporting wall and an insulating housing so that the connector can be rigidly mounted on the circuit board, and thereby can be kept in a position to be welded when it is transferred through a solder furnace, and will not slip off a mother board on which it is installed due to an operation on a module card to be inserted into the connector.
However, there are still many problems in such many proposed latching arms. For example, a latching arm tends to crack in unsuitable operation in the light of its tiny structure for the purpose of space saving or it is otherwise occupied spatially. Moreover, in terms of the latching accuracy, since the terminals mounted in the slot of the connector is very weak and thus could be damaged if the module card being inserted in the slot is over rotated. Even though the above mentioned R.O.C. Patent Application No. 84,100,813 has been directed towards and has attempted to solve such a problem, its structure is too complicated.